Sercomm NA502

The Sercomm NA502 is a ZigBee/Z-Wave gateway sold under various brands (e.g. A1 Smart Home Gateway in Austria). It is based on the MediaTek MT7621 SoC with a Gigabit Ethernet port.

Important Some variants, like the Vera gateway, seem to have a crippled U-Boot that don't allow loading code to SDRAM via TFTP. So far, no solution exists for those gateways.

ModelVersionSoCCPU MHzFlash MBRAM MBWLAN HardwareWLAN2.4WLAN5.0100M portsGbit portsModemUSB
NA502MediaTek MT7621ST880128NAND256MediaTek MT7603EN, MediaTek MT7662ENb/g/na/n/ac-1-1x 2.0

You need to attach a serial console to the unpopulated 4-pin header near the LEDs. With the front of the device facing towards you, the pinout is: GND - TXD - ? - RXD. The settings are 57600 8N1 and you should see a bunch of messages immediately after start.

  • Using the terminal, select option 1. Load system code to SDRAM via TFTP.
  • Put the initramfs OpenWrt image on your TFTP server and boot it.
  • You can then use SSH to connect to the OpenWrt running from RAM.
  • Transfer the OpenWrt squashfs image to the device (for instance to /tmp/openwrt.bin)
  • Run sysupgrade -n /tmp/openwrt.bin to install the image to your device.

The device contains a recovery image in the first partition. If the device is brand new, connect it to the Internet so that it auto-updates the second image. Afterwards, the device boots always from image 2 as longs as its checksum is correct.

If you don't install a valid OEM firmware to image 2 first, the auto-update stored in image 1 overwrites OpenWrt right away.

There are Z-Wave and ZigBee modules. Both can be exposed using ser2net so that another gateway solution can connect to it.

  • The Z-Wave module is at /dev/ttyS1 with 115200 8N1
  • The ZigBee modules is at /dev/ttyS2 with 57600 8N1
This website uses cookies. By using the website, you agree with storing cookies on your computer. Also you acknowledge that you have read and understand our Privacy Policy. If you do not agree leave the website.More information about cookies
  • Last modified: 2022/05/02 11:36
  • by tmomas